In general, inkjet printing machines or printers include at least one printhead that ejects drops or jets of liquid ink onto a media surface. An inkjet printer employs inks in which pigments or other colorants are suspended in a carrier or are in solution with a solvent. Once the ink is ejected onto media by a printhead, the carrier is solidified or the solvent is evaporated to stabilize the ink image on the media surface. The ejection of liquid ink directly onto media tends to soak into porous media, such as paper, and change the physical properties of the media. Because the spread of the ink droplets striking the media is a function of the media surface properties and porosity, the absorption of ink can adversely impact print quality.
Media needs to remain flat as it moves through an inkjet printer in order to avoid the ingress of the media surface into the gap between the printhead and the surface supporting the media. Irregularities in the flatness of the media affect image quality since the media may be positioned at angles to the ink drops ejected from a printhead or the media may brush or strike the face of the printhead. Consequently, maintaining the flatness of media, especially in the area opposite the printheads in an inkjet printer, is important. Printer configurations that enable the media to stay flat, therefore, are beneficial.